Knife sharpener



FIG. 1 is a perspective view of the knife sharpener in accordance withthe present invention;

FIG. 2 is a side view of the knife sharpener of FIG. 1 with the oppositeside being a mirror image;

FIG. 3 is a top plan view of the knife sharpener of FIG. 2;

FIG. 4 is an end view of the left end of the knife sharpener of FIG. 2;and,

FIG. 5 is an end view of the right end of the knife sharpener of FIG. 2.

The ornamental design for a knife sharpener, as shown and described.